can thieves steal a car without key

[MacDelilah]

Yes, thieves can absolutely steal a car without a key. Modern vehicles, despite advanced keyless entry systems, are vulnerable to sophisticated theft methods like relay attacks and signal amplification. These techniques exploit the technology designed for convenience, allowing thieves to unlock and start a car without ever possessing the physical key fob.

The most common method is the relay attack. Keyless fobs continuously emit a low-frequency signal. Thieves use one device to amplify this signal from inside your home (where the fob is likely kept) to a second device held near the car. The car is tricked into thinking the key is present, allowing the doors to be unlocked and the engine started. Another emerging threat is CAN injection, where thieves physically access the car's wiring (often through a headlight or wheel arch) to inject a message into the Controller Area Network (CAN bus), commanding the vehicle to unlock and start.

The table below shows data from the National Insurance Crime Bureau (NICB) and other sources, highlighting the scale of the issue and the most targeted vehicles, which often have high-performance variants.

Data Point	Value / Description	Source / Context
Top Theft Method for Keyless Cars	Relay Attack	Industry analysis from security firms like Tracker
Vehicles Targeted	Often luxury SUVs and high-performance models (e.g., Ford F-Series, Chevrolet Silverado, Honda Civic)	NICB "Hot Wheels" Report
Avg. Time to Steal a Car via Relay Attack	Under 60 seconds	UK Metropolitan Police data
Reported Thefts Using Keyless Entry Exploits	Significant percentage of all modern car thefts	Various law enforcement agencies
Effective Countermeasure	Signal-Blocking Faraday Pouch	Proven to block 99.9% of signal amplification attempts

To protect your vehicle, use a Faraday pouch (signal-blocking bag) to store your key fobs at home. Additionally, a simple, visible steering wheel lock acts as a powerful physical deterrent. For advanced protection, consider a GHOST immobilizer-type system that requires a unique PIN code to start the car, rendering relay attacks useless. Always park in well-lit areas and ensure your vehicle's software is updated, as manufacturers occasionally release security patches.

[McMarcus]

It's scary, but yes. They use these little electronic boxes. One person stands by your front door, and the other is by your car in the driveway. The box near your door picks up the signal from your key fob inside the house and passes it to the box by the car. The car thinks you're standing right there with the key. It unlocks and starts right up. My neighbor had his SUV stolen this way in under a minute. Now I keep my keys in a metal tin at night. It’s a real problem.

[McAiden]

Beyond the well-known relay attack, professional thieves are now using more invasive methods. A technique called CAN bus injection is gaining traction. Thieves break a small exterior light or access a wheel well to physically tap into the car's main computer network. By injecting a specific electronic command, they can mimic the signal from a valid key and start the engine directly. This method bypasses the key fob's security entirely and targets the vehicle's internal electronics, making it a serious concern for nearly all modern cars, regardless of the brand's anti-theft rating.